Light emitting diode has advantages of relatively small volume size, great power efficiency, long service life, low power consumption, and short warm-up time, etc., and thus has been used to replace conventional light source(such as an incandescent light bulb) and is widely applied in electroluminescence field. However, there is still a room for improving the reliability of a light emitting device package.
For the purpose of increasing the packaging density and decreasing the packaging size of a light emitting device, a conventional semiconductor device package with a quad flat no-lead (QFN) lead frame is provided with solder joints on a bottom surface of the QFN lead frame. However, when the solder joints of the conventional semiconductor device packages are intended for electrically connecting outwardly to external components, quality of the solder joints and completeness of electrical connection between the solder joints and the external components cannot be inspected simply by visual inspection.